3 research outputs found
Predicting the impact of climate change on range and genetic diversity patterns of the endangered endemic Nilgiri tahr (Nilgiritragus hylocrius) in the western Ghats, India
[Context] Climate change is considered an important factor affecting the distribution and genetic diversity of species. While many studies have described the influence of climate change on population structure at various scales, little is known about the genetic consequences of a changing climate on endemic species.[Objectives] To assess possible changes in the distribution and genetic structure of the endangered Nilgiri tahr (Nilgiritragus hylocrius), which is endemic to the Western Ghats in India, under climate change and human disturbances.[Methods] We integrated tahr occurrence and nuclear DNA data with environmental geo-datasets to project the response of tahr populations to future climate change with respect to its distribution, genetic diversity and population structure. We screened the environmental variables using MaxEnt to identify a manageable set of predictors to be used in an ensemble approach, based on ten species distribution modelling techniques, to quantify the current tahr distribution. We then projected the distribution and genetic structure under two climate change scenarios.[Results] We found that suitable habitat for tahr (9,605 km2) is determined predominantly by a combination of climatic, human disturbance and topographic factors that result in a highly fragmented habitat throughout its distribution range in the Western Ghats. Under the severe high emissions RCP8.5 scenario tahr populations may lose more than half of their available habitat (55.5%) by 2070. Application of spatial Bayesian clustering suggests that their current genetic structure comprise four genetic clusters, with three of them reflecting a clear geographic structure. However, under climate change, two of these clusters may be lost, and in the future a homogenization of the genetic background of the remaining populations may arise due to prevalence of one gene pool cluster in the remaining populations.[Conclusions] Our interdisciplinary approach that combines niche modelling and genetic data identified the climate refugia (i.e., the remaining stable habitats that overlap with the current suitable areas), where the tahr populations would be restricted to small, isolated and fragmented areas. Essential factors to avert local extinctions of vulnerable tahr populations are a reduction of human disturbances, dispersal of tahr between fragmented populations, and the availability of corridors.This research was supported by the Department of Biotechnology, Ministry of Science and Technology, Government of India, and by a German Research Foundation (DFG) fellowship awarded to RK (project number 273837911).Peer reviewe
Hunting record of endangered Marbled Cat <i>Pardofelis marmorata</i> in the Ziro Valley of Lower Subansiri, Arunachal Pradesh, India
We document a hunting record of a rare felid, Marbled Cat Pardofelis marmorata in Hija Village at the Ziro Valley, Lower Subansiri District of Arunachal Pradesh. The ecological knowledge on marbled cats is limited in this part of the geographic range of this species. However, the threats like the hunting directly impact the marbled cat populations. Initiatives to study the impact of the hunting practices and assessing the sustainability of these hunting practices on this species are required
Predicting range shifts of Asian elephants under global change
[Aim]: Climate change alters the water cycle, potentially affecting the distribution of species. Using an ensemble of species distribution models (SDMs), we predicted changes in distribution of the Asian elephant in South Asia due to increasing climatic
variability under warming climate and human pressures.[Location]: India and Nepal.[Methods]: We compiled a comprehensive geodatabase of 115 predictor variables, which included climatic, topographic, human pressures and land use, at a resolution of 1 km2, and an extensive database on current distribution of elephants. For variable
selection, we first developed 14 candidate models based on different hypotheses on elephant habitat selection. For each candidate model, a series of 240 individual models were evaluated using several metrics. Using three climatic and one land use change
datasets for two greenhouse gas scenarios, ensemble SDMs were used to predict future projections.[Results]: Nine predictor variables were selected for ensemble SDMs. Elephant distribution is driven predominantly by changes in climatic water balance (>60%), followed by changes in temperature and human‐induced disturbance. The results suggest that around 41.8% of the 256,518 km2 of habitat available at present will be lost by the end of this century due to combined effects of climate change and human pressure. Projected habitat loss will be higher in human‐dominated sites at lower elevations
due to intensifying droughts, leading elephants to seek refuge at higher elevations along valleys with greater water availability in the Himalayan Mountains.[Main conclusions]: Changes in climatic water balance could play a crucial role in driving species distributions in regions with monsoonal climates. In response, species would shift their range upwards along gradients of water availability and seasonal droughts. Conservation and management of elephant populations under global change should include design of movement corridors to enable dispersal of the elephant and other associated species to more conducive environments.MBA acknowledges funding from Spanish Ministry of Education CGL2015-68438-P project. PD and J-PP thank USFWS Asian elephant program (F12APO1186) and the International Elephant Foundation for financial support